scholarly journals The influence of boreal biomass burning emissions on the distribution of tropospheric ozone over North America and the North Atlantic during 2010

2011 ◽  
Vol 11 (9) ◽  
pp. 25099-25153 ◽  
Author(s):  
M. Parrington ◽  
P. I. Palmer ◽  
D. K. Henze ◽  
D. W. Tarasick ◽  
E. J. Hyer ◽  
...  
Keyword(s):  
North America ◽  
Biomass Burning ◽  
North Atlantic ◽  
Tropospheric Ozone ◽  
Free Troposphere ◽  
Scaling Factors ◽  
The North ◽  
Ozone Distribution ◽  
The North Atlantic ◽  
Satellite Instruments

Abstract. We analyse the tropospheric ozone distribution over North America and the North Atlantic to boreal biomass burning emissions during the summer of 2010 using the GEOS-Chem 3-D global tropospheric chemical transport model, and observations from in situ and satellite instruments. In comparison to observations from the PICO-NARE observatory in the Azores, ozonesondes across Canada, and the Tropospheric Emission Spectrometer (TES) and Infrared Atmospheric Sounding Instrument (IASI) satellite instruments, the model ozone distribution is shown to be in reasonable agreement with mean biases less than 10 ppbv. We use the adjoint of GEOS-Chem to show the model ozone distribution in the free troposphere over Maritime Canada is largely sensitive to NOx emissions from biomass burning sources in Central Canada, lightning sources in the central US, and anthropogenic sources in eastern US and south-eastern Canada. We also use the adjoint of GEOS-Chem to evaluate the Fire Locating And Monitoring of Burning Emissions (FLAMBE) inventory through assimilation of CO observations from the Measurements Of Pollution In The Troposphere (MOPITT) satellite instrument. The CO inversion showed that, on average the FLAMBE emissions needed to be reduced to 89 % of their original values, with scaling factors ranging from 12 % to 102 %, to fit the MOPITT observations in the boreal regions. Applying the CO scaling factors to all species emitted from boreal biomass burning sources led to a decrease of the model tropospheric distributions of CO, PAN, and NOx by as much as −20 ppbv, −50 ppbv, and −20 ppbv respectively. The impact of optimizing the biomass burning emissions was to reduce the model ozone distribution by approximately −3 ppbv (−8 %) and on average improved the agreement of the model ozone distribution compared to the observations throughout the free troposphere reducing the mean model bias from 5.5 to 4.0 ppbv for the PICO-NARE observatory, 3.0 to 0.9 ppbv for ozonesondes, 2.0 to 0.9 ppbv for TES, and 2.8 to 1.4 ppbv for IASI.

scholarly journals The influence of boreal biomass burning emissions on the distribution of tropospheric ozone over North America and the North Atlantic during 2010

2012 ◽  
Vol 12 (4) ◽  
pp. 2077-2098 ◽  
Author(s):  
M. Parrington ◽  
P. I. Palmer ◽  
D. K. Henze ◽  
D. W. Tarasick ◽  
E. J. Hyer ◽  
...  
Keyword(s):  
North America ◽  
Biomass Burning ◽  
North Atlantic ◽  
Tropospheric Ozone ◽  
Free Troposphere ◽  
Scaling Factors ◽  
The North ◽  
Ozone Distribution ◽  
The North Atlantic ◽  
Satellite Instruments

Abstract. We have analysed the sensitivity of the tropospheric ozone distribution over North America and the North Atlantic to boreal biomass burning emissions during the summer of 2010 using the GEOS-Chem 3-D global tropospheric chemical transport model and observations from in situ and satellite instruments. We show that the model ozone distribution is consistent with observations from the Pico Mountain Observatory in the Azores, ozonesondes across Canada, and the Tropospheric Emission Spectrometer (TES) and Infrared Atmospheric Sounding Instrument (IASI) satellite instruments. Mean biases between the model and observed ozone mixing ratio in the free troposphere were less than 10 ppbv. We used the adjoint of GEOS-Chem to show the model ozone distribution in the free troposphere over Maritime Canada is largely sensitive to NOx emissions from biomass burning sources in Central Canada, lightning sources in the central US, and anthropogenic sources in the eastern US and south-eastern Canada. We also used the adjoint of GEOS-Chem to evaluate the Fire Locating And Monitoring of Burning Emissions (FLAMBE) inventory through assimilation of CO observations from the Measurements Of Pollution In The Troposphere (MOPITT) satellite instrument. The CO inversion showed that, on average, the FLAMBE emissions needed to be reduced to 89% of their original values, with scaling factors ranging from 12% to 102%, to fit the MOPITT observations in the boreal regions. Applying the CO scaling factors to all species emitted from boreal biomass burning sources led to a decrease of the model tropospheric distributions of CO, PAN, and NOx by as much as −20 ppbv, −50 pptv, and −20 pptv respectively. The modification of the biomass burning emission estimates reduced the model ozone distribution by approximately −3 ppbv (−8%) and on average improved the agreement of the model ozone distribution compared to the observations throughout the free troposphere, reducing the mean model bias from 5.5 to 4.0 ppbv for the Pico Mountain Observatory, 3.0 to 0.9 ppbv for ozonesondes, 2.0 to 0.9 ppbv for TES, and 2.8 to 1.4 ppbv for IASI.

scholarly journals Molecular characterization of free tropospheric aerosol collected at the Pico Mountain Observatory: a case study with long range transported biomass burning plumes

2014 ◽  
Vol 14 (17) ◽  
pp. 24753-24810 ◽  
Author(s):  
K. Dzepina ◽  
C. Mazzoleni ◽  
P. Fialho ◽  
S. China ◽  
B. Zhang ◽  
...  
Keyword(s):  
North America ◽  
Organic Carbon ◽  
Molecular Characterization ◽  
Biomass Burning ◽  
North Atlantic ◽  
Air Masses ◽  
The North ◽  
Tropospheric Aerosol ◽  
The North Atlantic

Abstract. Free tropospheric aerosol was sampled at the Pico Mountain Observatory located at 2225 m a.m.s.l. on Pico Island of the Azores archipelago in the North Atlantic. The observatory (38°28'15'' N; 28°24'14'' W) is located ∼3900 km east and downwind of North America, which enables studies of free tropospheric air transported over long distances, mainly from North America. Aerosol samples collected on filters from June to October 2012 were analyzed to characterize organic carbon, elemental carbon and inorganic ion species. The average ambient concentration of aerosol was 0.9 μg m−3; on average organic aerosol contributes the majority of mass (57%), followed by sulfate (21%) and nitrate (17%). Filter-collected aerosol measurements were positively correlated (with an r2 ≥ 0.80) with continuous aerosol measurements of black carbon, aerosol light scattering and number concentration. Water-soluble organic carbon (WSOC) species extracted from two aerosol samples (9/24 and 9/25) collected consecutively during a pollution event were analyzed using ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry. FLEXPART retroplume analysis shows the sampled air masses were very aged (average plume age > 12 days). Approximately 4000 molecular formulas were assigned to each of the mass spectra in the range of m/z 100–1000. The majority of the assigned molecular formulas have unsaturated structures with CHO and CHNO elemental compositions. These aged WSOC compounds have an average O / C ratio of ∼0.45, which is relatively low compared to O / C ratios of other aged aerosol and might be the result of evaporation and increased fragmentation during long-range transport. The increase in aerosol loading during the measurement period of 9/24 was linked to biomass burning emissions from North America by FLEXPART retroplume analysis and Moderate Resolution Imaging Spectroradiometer (MODIS) fire counts. This was confirmed with biomass burning markers detected in WSOC species and with the morphology and mixing state of particles as determined by scanning electron microscopy. The presence of markers characteristic of aqueous-phase reactions of biomass burning phenolic species suggests that the aerosol collected at the Pico Mountain Observatory had undergone cloud processing before reaching the site. Finally, the air masses on 9/25 were more aged (∼15 days) and influenced by marine emissions, as indicated by organosulfates and other species characteristic for marine aerosol such as fatty acids. The change in air masses for the two samples was corroborated by the changes in ozone and the non-methane hydrocarbons ethane and propane, morphology of particles, as well as by the FLEXPART retroplume simulations. This manuscript presents the first detailed molecular characterization of free tropospheric aged aerosol intercepted at a lower free troposphere remote location in the North Atlantic.

scholarly journals Impact of North America on the aerosol composition in the North Atlantic free troposphere

2017 ◽  
Vol 17 (12) ◽  
pp. 7387-7404 ◽  
Author(s):  
M. Isabel García ◽  
Sergio Rodríguez ◽  
Andrés Alastuey
Keyword(s):  
Organic Matter ◽  
North America ◽  
North Atlantic ◽  
North American ◽  
Sea Salt ◽  
Free Troposphere ◽  
Aerosol Composition ◽  
The North ◽  
The North Atlantic

Abstract. In the AEROATLAN project we study the composition of aerosols collected over  ∼  5 years at Izaña Observatory (located at  ∼  2400 m a.s.l. in Tenerife, the Canary Islands) under the prevailing westerly airflows typical of the North Atlantic free troposphere at subtropical latitudes and midlatitudes. Mass concentrations of sub-10 µm aerosols (PM10) carried by westerly winds to Izaña, after transatlantic transport, are typically within the range 1.2 and 4.2 µg m−3 (20th and 80th percentiles). The main contributors to background levels of aerosols (PM10 within the 1st–50th percentiles  =  0.15–2.54 µg m−3) are North American dust (53 %), non-sea-salt sulfate (14 %) and organic matter (18 %). High PM10 events (75th–95th percentiles  ≈  4.0–9.0 µg m−3) are prompted by dust (56 %), organic matter (24 %) and non-sea-salt sulfate (9 %). These aerosol components experience a seasonal evolution explained by (i) their spatial distribution in North America and (ii) the seasonal shift of the North American outflow, which migrates from low latitudes in winter (∼  32° N, January–March) to high latitudes in summer (∼  52° N, August–September). The westerlies carry maximum loads of non-sea-salt sulfate, ammonium and organic matter in spring (March–May), of North American dust from midwinter to mid-spring (February–May) and of elemental carbon in summer (August–September). Our results suggest that a significant fraction of organic aerosols may be linked to sources other than combustion (e.g. biogenic); further studies are necessary for this topic. The present study suggests that long-term evolution of the aerosol composition in the North Atlantic free troposphere will be influenced by air quality policies and the use of soils (potential dust emitter) in North America.

scholarly journals Impact of North America on the aerosol composition in the North Atlantic free troposphere

2017 ◽  
Author(s):  
M. Isabel García ◽  
Sergio Rodríguez ◽  
Andrés Alastuey
Keyword(s):  
Organic Matter ◽  
North America ◽  
North Atlantic ◽  
North American ◽  
Free Troposphere ◽  
Aerosol Composition ◽  
The North ◽  
Westerly Winds ◽  
The North Atlantic

Abstract. In the AEROATLAN project we study the composition of aerosols collected over ~ 5 years at Izaña Observatory (located at ~ 2400 m a.s.l. in Tenerife, the Canary Islands) under the prevailing westerly airflows typical of the North Atlantic free troposphere at subtropical and mid-latitudes. Mass concentrations of sub10-µm aerosols (PM10) carried by westerly winds to Izaña, after transatlantic transport, are typically within the range 1.2 and 4.2 µg m−3 (20th and 80th percentiles). The main contributors to background levels of aerosols (PM10 within the 1st–50th percentiles = 0.15–2.54 µg m−3) are North American dust (53 %), non-sea-salt-SO4= (14 %) and organic matter (18 %). High PM10 events (75th–95th percentiles ≈ 4.0–9.0 µg m−3) and are prompted by dust (56 %), organic matter (24 %) and nss-SO4= (9 %). These aerosol components experience a seasonal evolution explained by (i) their spatial distribution in North America and (ii) the seasonal shift of the North American outflow, which migrates from low latitudes in winter (~ 32º N, January–March) to high latitudes in summer (~ 52º N, August–September). The westerlies carry maximum loads of nss-sulphate, ammonium and organic matter in spring (March–May), of North American dust from mid-winter to mid-spring (February–May) and of elemental carbon in summer (August–September). Our results suggest that a significant fraction of organic aerosols may be linked to sources other than combustion (e.g. biogenic); further studies are necessary for this topic. The present study evidences how long-term evolution of the aerosol composition in the North Atlantic free troposphere will be influenced by air quality policies and the use of soils (potential dust emitter) in North America.

Notes on Power Operated Controls for Large Aircraft

1945 ◽  
Vol 49 (410) ◽  
pp. 51-54
Author(s):  
A. Gouge
Keyword(s):  
North America ◽  
North Atlantic ◽  
The North ◽  
The World ◽  
The North Atlantic ◽  
Large Aircraft

A Study of the air routes of the world brings out almost at once the fact that some of the most difficult route are also the most attractive. For instance, the North Atlantic route which couples North America with Europe is certainly one of the most difficult in the world, but also by the fact that it couples two of the most densely populated, as well as the most wealthy groups of people in the world, one of the most attractive.

Sign in / Sign up

Export Citation Format

Share Document